Weld nut



May 3, l955 c. D. TRIPP ETAL 2,707,507

, wELD NUT Filed Feb. 6. 1950 /Nl/E/VTP b'esfer D. Tripp wn/fence W Kass,4 Tron/Veys United rates mensen' ,vtLn Nor Application February 6,3950, Serial No. 142,581

1 Claim. (Cl. 15b-413) This invention relates to a weldable nut adaptedto be permanently welded to a perforated metal plate to receive andlocate the threaded end of a securing bolt for other parts where, owingto space limitations the application of the standard type of nut to thebolt is not possible or can be accomplished only with great diiculty.Among other uses of such weldable nuts they have been effectivelyemployed for immovably securing machines in shipping crates, toadjustably secure supporting legs to machines, for the attachment ofhang r members or other parts to vehicle frames, and for analogouspurposes.

lt is the general object and purpose of the present invention to providecertain important improvements in a weldable nut of the piloted typedisclosed in application Serial No. 97,028, tiled by myself and LawrenceW. Kass on J une 3, i949, whereby the nut may be easily, quiclily andsecurely welded to a perforated metal plate with its threaded bore inaccurate axially centered relation to the perforation in said plate andthe Welded end face of the nut in exact parallelism with the surface ot'the plate, and if desired, in positive contact therewith throughout itsarea around the perforation by predetermining the relative size of thewelding projections and the Welding pressures and temperatures.

A more particular object of the invention resides in the provision ofwelding projections formed on the bottom face of a hexagonal nut atalternate corners only of the nut body and each having substantiallysingle point initial contact with the surface of a perforated metalplate, together with a novel arrangement of pilot rib or flange sectionsdisposed in angular relation to each other and the not bore and ofgreater height than the welding projections to freely extend into theperforation of the plate and cooperate with the Wall thereof toeffectively center the nut with respect to the perforation yet permitprecise parallelism between the opposed surfaces of the plate andwelding projections during the initial set up of parts as well as duringapplication of the welding heat and pressure to the nut.

A further object of the invention is the provision of a nut havingreadily controllable welding projections so shaped and arranged as toprovide maximum eiciency.

A more specific object in one embodiment of the invention resides in anovel relative location or rrangement of the Welding projections andangularly related pilot ribs on the end face of the nut body so thatwhen the ribs are inserted into a circular opening in the metal platethe outer side faces thereof are spaced from the wall of said openingand a part of the Welding flash metal flows into said spaces where ifdesired, it integrally joins the respective ribs to the plate, each ribcontacting the metal plate only at its opposite ends so that loss ofelectrical energy by short circuiting the current during the weldingoperation will be reduced to a minimum. Also by the relative angulararrangement of the piloting ribs, a series of nuts may be welded to aplate provided with hexagonal openings or apertures, with said nutsaccurately centered arent Cil Cil

with respect to the openings and oriented to the same positions, withoutemploying a jig for this purpose.

An additional object of the invention is to provide a weldable nuthaving the novel features above described without increasing theproduction cost of this type of nut and which can be expeditiouslyproduced in conventional nut makers by forming tools and dies and coldswaging operations.

With the above and other objects in View, the invention comprises theimproved weldable nut and the construction and relative arrangement oftl e several parts, as will hereinafter be more fully described,illustrated in the accompanying drawings and subsequently incorporatedin the subjoined claims.

ln the drawings, wherein l have disclosed several sim ple and practicalembodiments of the invention:

Figure l is a bottom plan vieu illustrating one commercial form of myimproved weldable nut;

Figure 2 is a side elevation thereof;

Figure 3 is a sectional View, substantially on the line 3--3 of Figurel, showiiw the nut in its initially applied position on the perforatedmetal plate;

Figure 4 is a similar View showing the nut in its final welded positionwith respect to the plate;

Figure 5 is a plan view of the nut in its welded position upon a platehaving a circular opening or aperture;

lFigure 6 is a similar view showing the weldable nut applied to a platehaving a hexagonal opening or aperture,

Figure 7 is a plan view similar to Figure l showing a slightly modifiedforni of the piloting means of the nut;

Figure 8 is a bottom plan view illustrating a further modification;

Figure 9 is a sectional View taken substantially on the line 9-9 ofFigure 8; and

Figure l0 is a fragmentary sectional view illustrating a slightlymodified form of the elding projections.

Referring first to the embodiment of the invention illustrated inFigures l to 5 of the drawings, We have shown a nut body it@ of ahexagonal forni having a tapped or threaded bore l2. Upon one end facelli of the nut body substantially hemispherical or dome-shaped Weldingprojections lo are formed, Pursuant to this invention only three ofthese welding projections are provided, each located at one end of amajor diameter or the nut body, or at alternate corners thereof, saidprojections at the nut face lli being substantially tangential toadjacent flat side surfaces of the nut body. By the provision of onlythree hemi-spherical welding projections perfect three point contact ofthe projections with the plate is assured, whereas with a greater numberol' projections such positive and uniform Contact of the projections canneither be made nor maintained. As a result of this three point contact,uniform ow of current is assured through each projection at all timeswith the result that substantially perfect utilization of thepredetermined amount of welding metal of each projection is assured,sputtering and excessive flash due to arcing between the plate and anon-contacting projection is eliminated, and insecure attachment of thenut to the plate due to a poor weld between the plate and non-contactingprojections is avoided.

Three pilotinfX ribs are also integrally formed with the nut bodyproject from the end face /l thereof te a greater height than thewelding projectie as seen in Figures 3 and of the drawings. Each orthese ribs has its lengthwise ension c. posed substantially at rightangles to a racial plane bis 'ing one of the welding projet, theopposilely beveled end faces f/Zfi ot' the rib L ng eqtndistantly spacedfrom said plane, while the outer side facp Vl of the rib is disposed ina plane substantially parallel to the nut axis and radially spacedinwardly from the welding projection i6 and the wall ci the perforationexcept at its outer corners. The inner side face 12d of each rib isinwardly inclined and at the nut face i4 is in substantiallv tangentialrelation to the threaded nut bore l2'. lt will thus be seen that thethree piloting ribs 18 define alternate sides of a hexagonal ligure withthe beveled ends 2i? oi adjacent ribs spaced apart about the nut bore l2and defining angularly spaced pockets 23 (Figure 3) for receivinginwardly flowing welding ash.

The length of the piloting ribs 13 and the spacing between these ribsand the welding projection i6 is predetermined with relation to the sizeor diameter of the aperture or opening in the metal plate to which thenut is to be welded. in Figure 5 of the drawings I have shown a metalplate 2e provided with a circular opening 2S. When the nut is arrangedin its initial position on one side of the plate 26, the three pilotingribs i8 lirst enter the opening 2S with the beveled end faces 2li ofsaid ribs in minimum clearance relation at circumferentially spacedpoints to the wall of the opening 2S, '1s indicated at 3l? in Figure 5.Each welding projection 16 then has a single point of bearing contact onthe surface of the plate 26 in radially spaced relation to the opening28, and

by reason of the chordal relationship of the ribs i8 to t the wall ofsaid opening, the welding liash receiving space 23 is provided betweensaid wall and the outer side face 22 of each rib i8.

Upon reference to Figure 5 it will be readily seen that the relativearrangement of the contact points of welding projections 16 and pilotingribs 1S with plate 2.o assures the maintenance of an accurate coaxialrelation between the threaded bore 12 and the opening 2S in the plate2o, during the welding operation. With the nut in its initiallyassembled position on the plate 26 as seen in Figure 3, the stationaryand movable welding electrodes are then applied, the movable electrodeforcing the nut under presaxial or lateral displacement with respect tosaid opening. The inclined inner surfaces 2d of the pilot ribs 18provide means tor directing and accurately centering an attaching boltin the end of the nut bore for easy and quick starting of the threadedconnection.

As above described the nut may be piloted by the ribs le in a circularopening 22% of the metal plate with the side faces of the hexagonal nutbody disposed in any desired angular relationship to the longitudinaledges of the plate. However, by providing the plate 26 with hexagonalopenings or apertures, as indicated at 3S of Figure 6 of the drawings, aseries or nuts may be easily and quickly oriented to the same positionon the plate 2o in axial parallelism to the openings Sii and then weldedto said plate in the manner above described.

ln this case the pilot ribs lS have substantial contact throughout theirouter side faces with opposite edge walls ot the hexagonal opening 38 inthe plate 26 so that the tlash receiving spaces 32 above referred to arenot present and the greater part of the welding flash will ilow betweenthe nut tace i4 and the plate 26 lengthwise of the pilot rib in oppositedirections from the point of initial contact ot projection l5 with plate25. However, in both cases it will be seen that the pilot ribs i8 serveas eiective barriers to inward ow of the welding ash to the bore 12 andresultant fouling of the nut thread. Further, it will be seen that owingto the angular relation of the pilot anges l5 to each other and the axisof the nut, and their points of contact with the wall of the opening 2Sor 3S with respect to the location of the initial points of weldingcontact between the projections i6 and plate 26 at the extreme ends oflonger diameters of the nut body, the tendency of torque stressesresulting from bolt sure toward the plate 26 as the electric heatingcurrent K passes through the nut body and the welding projections i6.The conventional method of resistance welding results in the concurrentapplication of heat and pressure to the projections i6 on the nut face,the electric current being of sucient amperage and maintained for thenecessary time to pass through the nut body and heat the projections 16and the surface portion of the plate 26 contacted thereby to a cherryred color, whereupon said projections and the surface portion of theplate are molecularly fused together.

application to rupture the welded connections between the face i4 of thenut and the plate 26 will be minimized.

In Figure 7 of the drawing a modification is shown in which instead ofthe spaced pilot ribs l a continuous pilot ilange or boss lll is formedon the end face 14 I of the nut having an internal and externalhexagonal in this welding operation the angularly related piloting j iribs le, due to the relation between their ends and the wall of theopening 2.8 in plate 26 maintain parallelism between the axis of the nutand. opening 2S until intimate contact is established between the nutface and the opposed surface portion of the plate 26 throughout itsarea. The excess welding flash from the projections i6 flows radiallyinward and into the spaces 23 between the piloting ribs and the wall ofopening 28 in the plate and retains sufficient heat to form, in elect,an integral connecting joint 3d between the outer face 22 of each riband the opposed wall surface section of opening 28 in the plate. A minorportion of the welding dash will also protrude outwardly on the surfaceof plate 26 beyond the corner of the nut as indicated at Since in thereduction of the welding projections 16 to a semi fluid condition by theelectric current, only a minor portion of each pilot rib 18 at its endsis an electrically conduc tive contact with the plate 26 detrimentalshort circulo ing of the current is reduced to a minimum, resulting inappreciable economy in the consumption of electrical energy.

Thus, my present improvements, as above described, provide a pilotedtype of nut having means whereby the nut may be easily, quickly andsecurely welded to the plate 26, with its threaded bore in exact axialparallelism to the opening in the plate, and against either rotative,

. boss 4l?. The arrangement of the shape. The several angularly relatedparts form an outer hexagonal guide section and the inner surfaces forma bolt guiding recess. ln this case, when the ange itl is inserted intocylindrical opening Z8 of the plate 26 to position the nut with respectthereto, only-the six external corners 4Z of said llange will haveContact with the wall of said opening, thus further reducing the area ofelectrically conductive contact between the pilot means and the plate towhich the nut is welded to an absolute minimum. When a nut of thisconstruction is applied to a plate having a hexagonal opening therein,each edge wall of the opening will be contacted by one of the angularlyrelated sections ot the pilot ilange or welding projections l6 on theend face of the nut with respect to alternate sections of the iiange 4@is the same as the relative arrangement of the welding projections withrespect to the pilot ribs i3 of the first described embodiment of theinvention.

ln Figures 8 and 9 of the drawings a further alternative embodiment ofthe invention is shown which has all of the advantages of theconstructions shown in Figures l and 7, in making the welded connectionbetween the nut and a metal plate having either a circular or hexagonalopening or aperture. in this case, the piloting boss or ilange 4d has anexternal hexagonal contour but is of internal cylindrical form andprovided with threads 46 in continuation of the threads of the tappedhere 12 of the nut body. The end ot the pilot boss 44 is also providedwith an internal chantier 48 to dircct and center the bolt end forstarting engagement with the threads 46.

ln Figure 9 the nut is shown in its initially applied position on ametal plate having a circular opening or aperture, and its finalposition, when welded to the plate in the manner above described, issubstantially` arcano? the same as that illustrated in Figure 4 of thedrawings.

In Figure 10, a modified form of the welding projection on the end faceof the nut body is shown, in which the point of Contact of the convexsurface of the projection 50 with the surface of the plate Z5 is locatedat a maximum radial distance from the adjacent side face of the pilotingange 18, and nearer to the corner of the nut body than in the previouslydescribed form of the invention, as indicated at 52. From this point ofmaximum height of the projection from the end face 14 o'i' the nut body,the welding projection slopes or inclines inwardly to the end face ofthe nut body approximately at the juncture of the outer side face of thepilot rib 18 therewith. This form of the welding projection insures aminimum of externally protruding 'welding flash with the major low ofmetal inward and circumferentially over a greater area between the endface 14 of the nut body and the opposed surface of the plate 26.

From the foregoing description, the construction and several advantagesof the disclosed embodiments of the invention may be clearly understood,and it will be seen that I have provided an improved construction andrelative arrangement of the pilot means and welding projections on theend face of the nut which may be readily proportioned to permit fullengagement of the nut aix-1i plate surfaces after welding, and providenuts which may be rapidly and accurately assembled upon perforated metalplates for resistance welding thereto, and in which the axial relationbetween the nut bore and the perforation of the metal plate will bemaintained during the welding operation. The invention also provides anovel pilot means for the nut having spaced parts contacting thc wall ofthe opening or perforation in the plate at points remotely spaced fromthe welding projections, so that rotation of the nut under torquestresses when the bolt is threaded into the nut bore, tending to disruptor break the welded connections, as would occur in the use of the usualannular or cylindricai pilot frange, is effectively prevented.

Since, in Figure 5 of the drawings the pilot ribs are joined by the weldflash 34 to the wall of the opening in the plate 26, and in Figure 6each rib has contact throughout its length with one of the edge portionsof the hexagonal opening in said plate, forces acting on the bolt at anangle to its axis cannot angularly dis-- place the bolt and nut relativeto the plate 26 so that the bolt axis will, under all conditions of use,be maintained in a position normal to the plane of the plate 26.

In each of the above described embodiments of the invention, l haveshown my present improvements :is applied to nuts of hexagonal form. Asimilar arrangement of the pilot ribs or boss and welding projectionsmay also be provided on connecting members of other polygonal forms, orof cylindrical form and having either a threaded bore or a plaincylindrical bore through which the bolt or other attaching element forthe part to be connected to plate 26 may be inserted. In each of theillustrated examples of the invention, the nut or other connectingmember is formed from cold drawn steel having a metallurgical structuresubstantially corresponding to that of the perforated plate to whichsaid member is to be welded. These members may be rapidly fabricated inwell known nut making machines in which the several parts are accuratelyformed as to their relative location and predetermined dimensions.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claim rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claim are therefore intended to be embraced therein.

What is claimed and desired to be secured by the United States LettersPatent is:

A hexagonal nut having a tapped bore and provided with means for forminga welded joint between an end face of the nut and a perforated metalplate, with the nut bore in accurate coaxial relation with a perforationin said plate, said means comprising spaced welding projections on saidend face of said nut body respectively located on alternate corners ofthe nut body and at one extreme end of each major diameter of the nutbody, and three piloting ribs on said end face of the nut bodypositioned between said bore and one of said projections insubstantially tangential relation to the bore thereof and each having alengthwise dimension extending equidistantly from and at substantiallyright angles to a radial plane bisecting one of said weldingprojections, said ribs being inwardly spaced from said projections andprojecting axially from the nut body for a greater distance than saidprojections, the ends of adjacent ribs being spaced apart to contact thewall of a circular perforation in the metal plate, with said projectionsin contact with the surface of said plate, to maintain parallelismbetween the opposed surfaces of the nut and plate during the weldingoperation, the outer side faces of said ribs being spaced from the wallof the perforation to provide spaces receiving welding flash from saidprojections to integrally unite said piloting ribs with the metal plate.

References Cited in the tile of this patent UNITED STATES PATENTS1,360,815 Suttill Nov. 30, 1920 1,872,616 Andren Aug. 16, 1932 2,042,953McArdle et al. June 2, 1936 2,054,187 Almdale Sept. 15, 1936 2,105,139Demboski et al Jan. 1l, 1938 2,167,285 Smith July 25, 1939 2,279,574Langmaid Apr. 14, 1942

